OpenGL改变位图图像的宽度高度

Question

我无法弄清楚如何增加图像的大小，我知道如何旋转，但我如何调整大小？此外，我想知道如何防止位图看起来压扁。现在，当我将它加载到屏幕上时，看起来两侧都被挤压了。

@Override
public void onDrawFrame(GL10 gl) {
    // clear Screen and Depth Buffer
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    // Reset the Modelview Matrix
    gl.glLoadIdentity();
    // Drawing
    gl.glTranslatef(0.0f, 0.0f, -5.0f);     // move 5 units INTO the screen
    gl.glMatrixMode(GL10.GL_MODELVIEW);

    gl.glRotatef(mAngle,        0, 1, 0);
    gl.glRotatef(mAngle*0.25f,  1, 0, 0);
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glRotatef(mAngle*2.0f, 0, 1, 1);
    gl.glTranslatef(0.5f, 0.5f, 0.5f);
    mAngle += 1.2f;
    bitmap_image.draw(gl);
}

在另一个类中，我用以下内容加载位图：

private FloatBuffer vertexBuffer;   // buffer holding the vertices
private float vertices[] = {
        -1.0f, -1.0f,  0.0f,        // V1 - bottom left
        -1.0f,  1.0f,  0.0f,        // V2 - top left
         1.0f, -1.0f,  0.0f,        // V3 - bottom right
         1.0f,  1.0f,  0.0f         // V4 - top right
};

private FloatBuffer textureBuffer;  // buffer holding the texture coordinates
private float texture[] = {
        // Mapping coordinates for the vertices
        0.0f, 1.0f,     // top left     (V2)
        0.0f, 0.0f,     // bottom left  (V1)
        1.0f, 1.0f,     // top right    (V4)
        1.0f, 0.0f      // bottom right (V3)
};

/** The texture pointer */
private int[] textures = new int[1];

public ImageLoader() {
    // a float has 4 bytes so we allocate for each coordinate 4 bytes
    ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertices.length * 4);
    byteBuffer.order(ByteOrder.nativeOrder());

    // allocates the memory from the byte buffer
    vertexBuffer = byteBuffer.asFloatBuffer();

    // fill the vertexBuffer with the vertices
    vertexBuffer.put(vertices);

    // set the cursor position to the beginning of the buffer
    vertexBuffer.position(0);

    byteBuffer = ByteBuffer.allocateDirect(texture.length * 4);
    byteBuffer.order(ByteOrder.nativeOrder());
    textureBuffer = byteBuffer.asFloatBuffer();
    textureBuffer.put(texture);
    textureBuffer.position(0);
}